This invention pertains to an apparatus for providing an inert environment in a gable top carton head space. More particularly, the present invention pertains to a form, fill and seal packaging machine that provides an inert gas in the head space area of a sealed gable top carton and a method for providing the inert environment.
Gable top cartons are in widespread use. In one typical use, these cartons are used for storing liquid food products such as milk, juice and the like. Numerous advances have been made in the manufacture and construction of gable top cartons. These advances include the incorporation of sealable spouts which provide ease of access, i.e., pouring, as well as enhanced reseal capabilities. Consumers have come to expect such enhanced carton designs and demand these increased performance characteristics.
In order to provide increased shelf life and xe2x80x9cfreshnessxe2x80x9d of product, form, fill and seal packaging machines presently incorporate various sterilization features. These features generally reduce or eliminate the microbes, such as bacteria, yeast and molds that might otherwise be associated with a packaging operation. It has been found that such sterilization steps can increase the shelf life of product so that fresh product can be provided in markets having less than optimal distribution systems.
It is well-known that although oxygen is a necessary part of our environment, it provides an optimum environment for the growth of microbes such as bacteria. To this end, regardless of the degree to which packages or cartons can be sterilized, the oxygen head space (that is oxygen within the volume of the carton that is not taken up by product), can provide an environment for microbial growth, and otherwise adversely effect the chemical composition of the product.
It has also been observed that oxygen can tend to take away from the flavor of certain products. For example, it has been found that oxygen that is present in the head space of cartons containing certain juices, such as orange juice can adversely effect the flavor of the juice. This is due to the natural oxidizing effect of oxygen. It has also been observed that such oxidizing can adversely effect the nutritional characteristics of juices and the like, again, by the natural deleterious effect that oxygen has on, among others, B vitamins and vitamin C.
Accordingly, there exists a need for an apparatus and method for providing an inert atmosphere or environment within the head space of a carton formed and filled on a form, fill, and seal packaging machine. Desirably, such an apparatus and method provides an environment that reduces or eliminates microbial growth within the package. Most desirably, such an apparatus and method provides an environment that enhances flavor retention and the nutritional characteristics of the packaged product, and maintains the hygienic and sterility levels and standards of the packaged product.
A head space inerting system is for use on a form, fill and seal packaging machine for forming, filling and sealing packages. The head space inerting system includes an inerting gas source, an inerting gas heater and an inerting gas nozzle assembly. The system is configured to directly introduce the inerting gas, preferably nitrogen, into the package head space, above the packaged product.
In a current embodiment, the inerting system is used on a form, fill and seal packaging machine having a having a filling station, a top heating station and a sealing station, and the nozzle assembly is disposed between the top heating station and the sealing station.
The nozzle assembly includes an inlet, a plenum defining a flow space and a dispersion plate. The dispersion plate is formed as a wall of the plenum. The nozzle assembly can include flanges that extend from the plenum in a plane that is spaced from a plane defined by the dispersion plate.
The nozzle is configured for positioning between upstanding fin panels of the package. The dispersion plate is disposed below the tops of the fin panels, and the flanges extend over the fin panel tops. This directs the flow of inerting gas into the package and provides a flow path for air leaving the head space to exit the package. A preferred dispersion plate is formed as a foraminous plate.
The inerting system can include an inerting gas valve assembly and an inerting gas filter/regulator assembly. The valve assembly and filter/regulator assembly are disposed between the inerting gas source an the inerting gas nozzle.
In a preferred system, the inerting gas heater is formed as a heat exchanger supplied by, for example, an electrical resistance heating system heat source or other heat exchange medium such as steam. A current system includes a coil-type heat exchanger having a coil side and a shell side. The inerting gas is directed through the coil side of an electrical resistance or other heating medium is applied to the inner shell.
A form, fill and seal packaging machine having the head space inerting system is contemplated by the present invention and includes a filling station, a top heating station and a sealing station. The nozzle assembly is disposed between the top heating station and the sealing station. A contemplated machine is an extended shelf life (ESL) or aseptic filling machine that requires a sterile environment.
A method for inerting the atmosphere in the head space of a package formed on a form, fill and seal packaging machine includes the steps of forming a package, filling the package with a product, introducing an inerting gas above the product in the package subsequent to filling, and sealing the package with the product and the inerting gas therein.
In a preferred method, the inerting gas is nitrogen. For certain products, the inerting gas can be water vapor (H2O), carbon dioxide (CO2), argon or other gases known to those skilled in the art. Most preferably, the method includes the step of heating the inerting gas prior to introducing it into the head space of the package. In one method, the heating step includes the step of directing the inerting gas through one side of a heat exchanger and providing a heating medium through another side of the heat exchanger. Preferably, the inerting gas is filtered and regulated prior to introducing it into the package head space.
These and other features and advantages of the present invention will be apparent from the following detailed description and the accompanying drawings, in conjunction with the appended claims.